Door mechanism



Nov. 16 1926.

' 1,6,976 C. C. TOMKINSON Doon MECHANI'SM INVENTOR ATTORNEY.

, `Patented ^Nov.- i6, 1926.`

UNI-TED- kSTATES This,.,invetion relates to" doors and -parhouses, pier sheds or like structures.

` 5 ally made in sections and to ropen the doors, the sections are raised to overlapping position and are then swung laterally or inwardly to inclined position, thus conserv- 4 ing headroom. Such doorsare very large l and heavy in yconstruct-ion and to facilitate the operationthereof, counterweighting means is provided. -l A In one form of construction,tracks are used'to cooperate with rollers `or lugs on the 5 door to swing the doorV sections inwardly and to guide and support the sections as they are moved to inclined or horizontal2 pos1tion. Such tracks have curved portionsfor swing- 4 ing the sections vand substantially/,horizontal 0 portions for supporting and guiding the sections after they have been swung from the vertical into inclined position;

In order to eectivel .counterbalance doors of the t-ypespecie there are three i 5 different stages or' conditions which must be vmet during the opening a'ndclosing of the door. N One counterbalancing conditionl is encountered hwhen' the lower section is raised I to a position overlying the upper section.

- The second stage is encountered when the two 'sections are traveling in the curved portion of thetrack and are swinging out of the vertical plane to a position inl which the l' upper end of the combined sections are disposed on the horizontal portion of the track.

-The third stage is encountered asr the upper ends of the combined sections travel on the horizontal portion of the track and thedoor is lswung'to its wide open or, inclined position. e.

During the first stage when the lower sec- -tion is .rising .to a position overlying the -upper section, the count-erweight required is equal to the weight of the lower section.

' During the second stage the counterweight l required varies from the full weight of the y combined sections at the start to one half of the weight of the combined sections at the end of this stage 4when the upper ends of the combined sections are' sup orted on the horizontal ,portion -of the track. d

ends of e eombinedsections travel on the ticularly to doors of the type used'ingware-v Doors of the characterfspeciied' are 'usu wide open position.

Duringh the third stage when the upper 1,606,915 PATENT-OFFICE. y

' CHARLES C. TOMKINSON, OF 'PLAINFIELD, NEW JERSEY, ASSIGNOB T0 J. EDWARD l I j OGDEN, 0F MOUNTAINVILLE, NEW YORK. l l

noon MEc'HANIsm "Appunti-0n med February 29; 1924. 'serial-No. sesgos.

horizontal portion of the track-the 'counterweight required is-equal to oiie half -of the weight ofthe combined sections.

'To meet these conditions it is necessary that counterweighting means be so connected tothe door sectionsi that the counterweighting effect will vary in accordance with the requirements and will counterweight'the lower section during the firstA stage and the combined sections during the second and third stagesv and in counterweighting the' combined sections, the counterweighting effeet should be reduced from a counterweight equal to the full weight of both sections to a counterweight equal to `one half of the .combined sections.

This invention has for its -si'ilientobject,

therefore, to provid counterweighting mechanism for doors o constructed and arranged that a substantially perfect counterbalance vwill bq elltected in all positions of movement of the door sections.

Another objectof the invention-isto provide a counterweighting mechanism for doors so constructed and so connected tothe doors thatthe counterweighting effect will be variedl in accordance 'with' the requirements therefor during the opening and closing movements of the door.

Further objects )of the invention will appear. from the following specification taken in connection with the drawings, which forni a part of this application, and in which- Fig. 1 is a sectional' elevation of the door constructed in accordancewith the invention, the door sections being shown in closed position. Y

Fig. 2 is a view similar to Fig. 1 but showing the lower section raised to a positiony overlying the upper section.- L

Fig. 3 isa view-similar to Figs. 1 and A2, but showing the combined sections after they have finished their travel in thecurved portion of the' track and `have Ireached the' horizontal, portion of the track.

Fig. 4 is a view similar to Figs. l to 3, but showing the vcombined sections in Fig. 5 is an lelevational viewF partly broken weight foreach section instead of a single counterweightjfor both sections. Y .y

their l awayshowing the use' of a separate counter- Fig. 6 is a tran'verse sectional view taken..

substantiallyon line 6-6 'of Fig. 1.

135 section.

Fig. 7 is a sectionalviewA taken substantially on line 7--7 of Fig. 1, and

Fig'. 8 is an elevational view partly in tions and the gist of the invention consistsY in so connecting counterweighting means to the upper and lower door sections'that the l counterweighting eli'ect will conform to the counterweighting requirements during all portions of the cycle of operation of the door sections. In order to accomplish these results and to vary the counterweighting effeet as the requirements vary, the horizonl tal and vertical components of the counterweighting force are varied or varyingly neutralized in accordance with the counterweighting requirements during the movement of the upper ends of the door sections around the curved portions of the tracks and are fully neutralized during'the travel I on the horizontal portions of the tracks. It has been found this can be accomplished by properly coordinating the locations of the pivot for the sheav'e over which the cable passes that connects the counterweight to the upper door section and the point of connection of this cable `to the upper door It has been determined that the l point of attachment of the cable to-'the up- \per door section which gives this coordina-j tion, travels substantially in the path of an' v involute curve` described aboutthe periph- 40 veryl of the sheave over which the cable passes le the upper ends of the door sections travel along the horizontal portion of the track, When this point hasbeen located properlywith reference to the -pivot of the sheave, there will be no mot-ion ofthe sheave during the movement of the upper ends of the door sections along the horizontal portion ofthe track and no movement of the chain' passing over the sheave to the counterweight and consequently no4 counterweighting efect.` AThe problem is, therefore, solved by so relatively locating the pivot of the sheave and the point of connection of- `the cable to the upper door section that the point of attachment to the cable of the-upper door section will travel in an involute curve described about the periphery of the sheave. Another way of stating this. problem is that whenv the cable is connected to the 50v proper point on the upper section, the stress .in the cable is resolved intol vertical and l horizontal components whose moments are equal and opposed so that one fully neutralizes the other Iduring the'travel on the 5 horizontal portion of the track. .Further de- The invention has been worked out in contails of thelinv-ention willl appear from the J following description.

In the drawings there. is illustrated a two section door 4coriiiirising a lower section 10 and an upper section 11. The lower section 1 0 has secured to its edges in brackets 12,v

`ii'ig'portions 16 of, the lowerv door section,

thus guiding this section in -'its upward movement. The lower section has secured thereto lugs 1'( adapted to engage the under surface of the lower end 18 .of the upper sec-I -tion 11 when the lower section has been moved to a position overlapping the upper section as shown in Figs. 2, 3 and 4.

In the p articular embodiment of the invention shown, the means for moving the doors inwardly after the lower section is elevated to a position overlying the upper section, comprises a pair of guiding and supporting tracks 19 secured in any suitable mani'ier to the frame structure of the building and having grooves 2() in'which are positioned rollers or lugs 21 mounted on the side edges of the upper door section 11. The tracks 19 have curved portions 22 for breaking in the door oi swinging the door out of the vertical plane and substantially horizontal portions 23 for guiding the doors as they are swung to inclined position and vfor assisting in supporting the doors after the rollersf21 reach the of the tracks.

As above stated, counterbalanc'e the doors in all positions of horizontal portions their movement one half of the counter-A weighting eifectshould he available lduring the movement of zthe lower door to a position overlying the upper'door section and one half'of the counterweighting effect should be available after the doorshave reached the position shown in Fig. 3, namely, thel posiin order to effectively.l

tion in which the rollers 21 have reached the horizontal portion 23 of the tracks. During the movement ot' the doors from the position 'shown in Fig. 2 to the position shown in Fig. 3, the counterweighting ef'ectshould b e varied from the full counterweigliting effect at the start to one half of the counterweighting effect' at the completion of this portion of the movement. f

means of which these results are accomplished will now .be described.v In the embodiment of thei'nvention .shown in Figs. 11 to 4 inclusive a single counterweight or a pair of single counterweights is provided for both door sections" although as 'shown in Fig. 5 a separate counter-weight could` be4 `provided for each door section.y When both sections weigh substantially thesame, the single counterweight or the pair of: single counterweights is preferable. In this construction, `a counterweight has secured thereto a sheave 31 around which passes a cable 32. The cable 32 has one length thereof extendingaround a sheave 33 mounted l on a shaft or pivot .'34 at a predetermined fixed point and the end ofthis length of cable is connected to the lower door section '.10 adjacent to thelower end thereof as shown at 35. The other length of the' cable v 32 passes around a sheave 36 looselymounted on the pivot or shaft 34 and the end of this length of cable is connectedto the upper door section at a suit-ablev point such as the point '37, the' location of which will be hereinafter' described. Sheaves 33 and 36 are preferably provided at each end of the shaft 34 and a'counterweight 30 is connected to the door sections at both side edges thereof. Any suitable operating means`- for hoisting the door sections may be utilized such, for example, as mechanism vfor rotating sheaves 33.

Since4 one end of the cable 32 is connected to the lower ldoor section and since during the first stage of movement of the door sections the upper section .does not move, it will be evident that onehalf of the weight of the counterweight 30 will be effective during lthe position shown in Fig. 1 to the position shown in Fig. 2. l l.

" Moreover, since the point 37 of connectionsy of the cable 32 to the'upper door section 11 is located between the^upper and lower edges thereof, preferably above the center, the horizontal and vertical components of the counterweight force] will be varied during 1 the movement of the door sections from the position shown in Fig. 2 to the position shown in Fig. 3 as the point 37 moves out- Q wardly Aaway from the initial vertical plane of the door section 11. Therefore, the coun- .y terweight force acting on' the door sections y will be decreased during the movement of the door lsections around the curved portion of thel track. The realproblem to be solved, therefore, is to so locate the point 37 with reference to the pivot 34 that the effect of the counterf` weight on the door sections will be reduced one half the full counterweighting 'effect when the sections reach the position -shown in Fig. 3 and during their movement from y this, position to the wide open position shown 4 inl Fig. 4. In order to accomplish this, the sheave 36 around which thev counterweight cable passes to the upper door Asection should remainl stationary after the doorsl have reached the position shownin Fi 3. If u this is effected, then the .counterweight will act only through the connection to the. lower ,y door section..` a

movement of the lower section from the One method of accomplishing 'this result last stated is shown in Fig. 8 and it has been found Athat for each location of the point 37 of connection between the cable 32 and the upper door section, there is a corre'- sponding correct location for the pivot 3'4 of the sheave 36. Since the sheave 36 is not to rotate during this-period of movement of the door sections, it will be obvious that the length of cable. between this sheave and the upper door section should unwind from the'peripliery ofthe'v sheave; This being so, the point of connection to the upper door sec'tion mustv move in an involute described about the periphery ofthe. sheave 36 or approximately'in such .-a path.

The curve X shown in Fig. 8 is in an involute curve generated around the periphery .of the sheave wheel 36. By plottmg the varlous positions taken by a point such as 37 o nthe upper door section when this door sectlon moves from the position shown in Fig. 3'and diagrammatically in Fig. 8 tothe wide open position shown in Fig. 4 and diagrammatically in F ig. 8, it has been determined that these pointslie in `a curve which I- I can be located on the' involute curve X provided the pivot 34 of the sheave is properly located and correlated t'o the particular point chosen' for the counterweight cable connection. l

Referring to Fig. 8the point M is Ilocated substantially at the center of the com- 'bined door sections and the points O, P

and Q are spaced apart equalv distances above the pointvM. The curves M-M,l N-N, O O, P-P and Q-Q represent the paths of travel of the points M, N, vO,

P' and Q as .the door sections move from the positions shown in Fig. 3 to the position shown in Fig. 4.

The points M', N, O', P and Q represent the corregt corresponding positions for .the pivot,34. These points, M N O, P', and -Qf were found in the following manner. To locate the point M the involute curve was superimposed on the line M-M and rotated until a portion of this curve, as shown in Fig. 8, was found to substantially coincide with the curve M-M generated by the point M as the door vwas moved from one position shown in Fig. ."8 to the other position showntherein. When a portion ofthe involute curve coincided in the manner set forth with the curveM-I- M, the Acenter of the involute' located the point nM. The points Nf, O', P and Q were similarly located and in each instance it was noted that no other ortion of the curve could be made to coinc'i e with the generated-curve M-M, N,'N, O-O, P- P and Q-"Q. The portions of the involute-whichwere found to coincide with the generated curves are indicated on the involute by the letters M-M,

f In practice the sheave wheel 36 must always be located in some position at or above the plane of the horizontal portion of the track and, therefore, the point of connection 37 must be located somewhere between the. center and the upper end of the combined' door sections and for each point of attachment so located a corresponding point.

' of location for the vpivot 34 can be found.

It is well known in this art that a door of the character described has considerable vfriction in operation and that a practical f balance can always be obtainedby an approximation of the correct theoretical balance. y It should be'understood, therefore, -that the' invention is not limited to an exact point of attachment l'37 for a given sheave 'position'or a given position of the pivot 34 but that points located adjacent' these points will give a practical balance.

It should also be understood that the invention is not limited to the use of a single counterweight for balancing both door sections'but'that a separate counterweight may be used for each door section, if desired, as

I shown in Fig. 5. In this case, each counterweight should correspond in weight to the weight'of the door section to which 1t is connected and the point of connection 37 can be varied to suit the circumstances. For

' instance, if the lower section is considerably heavier than the upper section, then the connection 37 should be. made at a point to overcome this condition during themove- 'ment -of the-door sections between the positions shown in Fig. 8. In this case, as the counterweight would weigh. more than half of the combined sections during the `'second and'thircl periods, the connection `shouldbe above the neutral point or above l the point at which the counterweighting force exerted through the cable passing over the sheave 36 is neutralized. In other words,

for the location of the sheave at M', N,'O, P or Q', the Vconnection of the cable to ,the door section should be above the point M, NO, P, or Q. Under this condition,

the sheave vwheel'36 will rotate in .an -anticlockwise direction during the movement of the'door sections through their third stageV of .opening movement.

From the fore oing description, it will be seen that ametod has been provided for accurately determining the correct locations of the'- pivot for thefheaves and the'jpoint Y of connection ofthe cable to the upfper door Asection and thatV with these two points so determined the door will'be eifectively coun- I. terbalanced in all positions of-its movement.`

, z Although certain specific embodiments of the invention have been Vparticularly shown- 'p and described, it will beunderstood that the invention is capable of modication and that changes in the construction and in the arrangement of the various cooperating 'parts may be made without departing from the spirit or 4scope of the invention, as expressed in the following claims.

What I claim is:

1. Door mechanism comprising-a plurality of l door sections movable vertically and laterally, tracka means for guiding said sa@ tions laterally, said track means having an inclined portion and a substantially horizon-- tal portion, counterweighting means for said door sect-ions connected'to the lowen door section adjacent the lower end thereof and to the upper door s lction intermediate the upper and lower ends thereofD and sheaves disposed above the path of movement ofthe door sections and over which the connecting cable 'passes from the -counterweighting means tothe door sections, 'one of said sheavesv being so located that the path of movement of the point of connection of the cable'l to the upper door section will substantially coincide with a portion of an in! volute curve generated around the pe riphery of the sheave Wheel from which the cable passes to the upper door section when' the upper ends of the door sections are being guided along the horizontal portion ofthe track. I f

2. Dooramechanisln comprising an upper door section and a lower door section movable vertically and laterally, said lower section being movable to a` position overlying the upper section and both of said sections being subsequently movable in unison vertically and laterally to inclined positiom.

means and sheaves intermediate said coun-v terweighting means and said door sections for supporting and guiding said lflexible means, one of said sheaves 'being so located relative to the point of connection lof the.

flexible means to the upper door section that said point of connection to the upper door section will travel substantially in an involute pathV about the periphery of the sheave wheeljovcr which thel iexible means passes to saidupper door section when the upper ends of the door sections are guided in a substantially horizontal path.

3. lDoor mechanism comprislng `an upper.l

door section anda lower door section movable vertically and laterally, said lower section beingjmovable to a position-overlying the upper 'section and both of'said sections being subsequently movablein unison vertic-allyV andv laterally ,toinclined position,

means for guiding theupper ends of said .sections in an inclined path and-in a subenel thereof and to said upper door section intermediate .the upper and 'lower edges thereof, said counterweighting means bemg 'connected to the sections by flexible means and sheaves intermediate said counterweighting means and saiddoor sections for supporting and guiding said flexible means, the sheave' over whichv the -ilexible means passes to vthe upper door'section being so located with reference to thexpoint'of connection of said iiexible means -to vsaid upper.

Y'door sect-ion that -said sheave will remain tionsv laterally, said track means having an inclined portion and a substantially horizontal portion, counterweighting means ,for said door sections connected to the lower door section adjacent the lower end thereof and to the upper door section intermediate the upper and lower ends thereof and sheaves mounted on a pivot disposed above the path of movement- ,of the door sections and over which the -connecting cable passes from the counterweighting means to the door sections, the sheave over which the cable passes to the upper` door section being so located relative to the point of'attachment of the cable to the upper door section that ltravel of the door sections and a cable passing around the counterweight sheave and over the sheaves and having one end connected to th'e lower door section adjacent the bottom thereof and the other end connected to the upperdoorsection above the center thereof.

7. Doormechanism comprising a door movable vertically and laterally, track means for guiding the door laterally, said track means having an inclined portion and a substantially horizontal portion, counterweighting means for saiddoor connected to thedoor intermediate the upper and lower ends thereof and sheaves vdisposed above the path of movement ofthe door and over which the counterweighting cable passes vfrom the counterweighting means to the door, the pivot of one of said sheaves being so locatedthat the path of `movement of the pointv of connection of' the lcable which passes over said sheave to the ldoor inter- .mediate the upper and lower ends thereof will substantially1 coincide with :a portion of anpinvolute curve generated around the periphery of said sheave when :the upper end of the door is .being guided along the horizontalv portion ofthe track.

8. Door mechanism 4com rising a -do or movable vertically land aterally, track of the door has a vertical component of movement and in a path'in which the upper end of the door moves in a ysubstantially horizontal path, counterweighting means for said sheave will remain substantially Sta-#the door connected to the door adjacent the tionary during the travel ofthe upper ends' of the door sections along the horizontal portion of said ltrack means. Y

Y portion,- counterweighting means 'for said door sections connected to-the lower door -section adjacent the lower end thereof and to the upper door section at a point above -the center thereof, andA sheaves disposed above the path of movement of the door sections and over which vthe connecting cable passes from the counterweightingvmeans to the door sections.

6. Door mechanism comprising a plurality of door sections movable vertically and'llattially horizontal position-, and countererally, track means for sald sections laterally and guiding 'and supportingl the sections as they move to inclined or substanweighting means comprising a counterweight, a sheave on sa1d counterweight, a

pair of sheavesdisposedabove'the path of Y lower end thereof-and intermediate the uptravel of the door ,and over which the-connecting cable passes from the counterweighting means to the intermediate point' ony the door, said sheave being so located relative to said'intermediate point that the sheave will `remain substantially stationary during the travel of the upper end of the door along the horizontal portion of the track means.

9. A` door comprising upper and lowei` sections arranged to move together vertically and laterally, track means for the sections laterally, a counterb' ancin mechanism comprisinga counterweight, an a connecting means between the Y counterweight and d the upper door section arranged to produce an upward ,pull lom the upper doors'ection, and meansl for neutralizing said upward pull at a predetermined part ofthe movement of the two vdoor sections. A

my hand this 13thday of February, 1924:.

CHARLES c, TOMKINSON.

means for guiding the door laterally, said' 'ding v In witness whereof, I4 have hereunto set` 

